## Add or remove a reaction to a message

`client.Messages.AddReaction(ctx, messageID, body) (*MessageAddReactionResponse, error)`

**post** `/v3/messages/{messageId}/reactions`

Add or remove emoji reactions to messages. Reactions let users express
their response to a message without sending a new message.

**Supported Reactions:**

- love ❤️
- like 👍
- dislike 👎
- laugh 😂
- emphasize ‼️
- question ❓
- custom - any emoji as a tapback (use `custom_emoji` field to specify)
- sticker - an emoji or image peeled onto the message (use `emoji`, `url` or `attachment_id`)

**`custom` and `sticker` are different products.** A `custom` reaction is a
tapback: the emoji sits in a small bubble on the corner of the message. A
`sticker` is peeled onto the bubble itself, and can be dragged, resized and
rotated. Both accept an emoji; they do not look alike.

**Stickers** are iMessage-only and cannot be removed, so
`operation: "remove"` with `type: "sticker"` is rejected. Position, size
and rotation are optional via `placement`, and can be changed afterwards
with `PATCH /v3/messages/{messageId}/reactions/{reactionId}`. An animated
image peels as an animated sticker, in whatever shape the file already has.

**Polls** take stickers only. Any tapback on a poll message — standard or
`custom` — is rejected with a 400.

### Parameters

- `messageID string`

- `body MessageAddReactionParams`

  - `Operation param.Field[MessageAddReactionParamsOperation]`

    Whether to add or remove the reaction

    - `const MessageAddReactionParamsOperationAdd MessageAddReactionParamsOperation = "add"`

    - `const MessageAddReactionParamsOperationRemove MessageAddReactionParamsOperation = "remove"`

  - `Type param.Field[ReactionType]`

    Type of reaction. Standard iMessage tapbacks are love, like, dislike, laugh, emphasize, question.
    Custom emoji reactions have type "custom" with the actual emoji in the custom_emoji field.
    Sticker reactions have type "sticker" with sticker attachment details in the sticker field.

  - `AttachmentID param.Field[string]`

    Reference to a sticker image pre-uploaded via `POST /v3/attachments`.
    Only valid when type is "sticker".

    Exactly one of `emoji`, `url` or `attachment_id` is required when
    type is "sticker".

  - `CustomEmoji param.Field[string]`

    Custom emoji string. Required when type is "custom".

    This is a **tapback** — the emoji sits in the tapback bubble on the
    corner of the message. To peel an emoji onto the message as a
    draggable sticker instead, use type "sticker" with `emoji`.

  - `Emoji param.Field[string]`

    A single emoji to peel onto the message as a sticker. Only valid
    when type is "sticker".

    Exactly one of `emoji`, `url` or `attachment_id` is required when
    type is "sticker".

    Not to be confused with `custom_emoji`, which produces a tapback.

  - `PartIndex param.Field[int64]`

    Optional index of the message part to react to.
    If not provided, reacts to the entire message (part 0).

  - `Placement param.Field[MessageAddReactionParamsPlacement]`

    Optional position, size and rotation of a sticker on the target
    bubble. Only valid when type is "sticker".

    Every field is independent and optional — omit the object entirely,
    or any field within it, to keep the default (centred, default size,
    unrotated).

    - `Rotation float64`

      Clockwise rotation in degrees.

    - `Scale float64`

      How large the sticker is drawn. Omit it for the default size —
      equivalent to `1` for an image, or `0.5` for an emoji.

      Values outside 0.05–2.5 are clamped rather than rejected.

      Scale is linear, so 2.5 is a little over six times the area.

    - `X float64`

      Horizontal position on the target bubble, from -1 (far left) to
      1 (far right). 0 is centred.

    - `Y float64`

      Vertical position on the target bubble, from -1 (top) to
      1 (bottom). 0 is centred.

  - `URL param.Field[string]`

    Linq attachment URL of the sticker image — the `download_url`
    returned by `POST /v3/attachments`. Only valid when type is
    "sticker".

    The image must already be stored with us. To send a sticker from
    elsewhere, upload it with `POST /v3/attachments` first and pass
    `attachment_id`.

    Exactly one of `emoji`, `url` or `attachment_id` is required when
    type is "sticker".

### Returns

- `type MessageAddReactionResponse struct{…}`

  - `Message string`

  - `Status string`

  - `TraceID string`

### Example

```go
package main

import (
  "context"
  "fmt"

  "github.com/linq-team/linq-go"
  "github.com/linq-team/linq-go/option"
  "github.com/linq-team/linq-go/shared"
)

func main() {
  client := linqgo.NewClient(
    option.WithAPIKey("My API Key"),
  )
  response, err := client.Messages.AddReaction(
    context.TODO(),
    "69a37c7d-af4f-4b5e-af42-e28e98ce873a",
    linqgo.MessageAddReactionParams{
      Operation: linqgo.MessageAddReactionParamsOperationAdd,
      Type: shared.ReactionTypeLove,
    },
  )
  if err != nil {
    panic(err.Error())
  }
  fmt.Printf("%+v\n", response.TraceID)
}
```

#### Response

```json
{
  "message": "Reaction processed",
  "status": "accepted",
  "trace_id": "trace_id"
}
```